Conventionally, there has been known a digital microscope that picks up an image of a sample using bright field lighting or dark field lighting. In a bright field observation performed using the bright field lighting, light parallel to a magnifying optical system is irradiated on a sample and reflected light of the light is observed. On the other hand, in a dark field observation performed using the dark field lighting, scattered light and reflected light generated by obliquely irradiating light on a sample are observed.
Patent Literature 1 proposes a magnifying observation device that can perform both of the bright field observation and the dark field observation. The magnifying observation device described in Patent Literature 1 includes an optical fiber cable incorporating a first optical fiber bundle connected to an epi-illumination section and a second optical fiber bundle connected to a side illumination section. The magnifying observation device switches, with switching means included in a body section, whether light from a light source is led into the first optical fiber bundle.
In Patent Literature 1, when the light is not led into the first optical fiber bundle, the side illumination is performed through the second optical fiber bundle. When the light is led into the first optical fiber bundle, both of the side illumination and the epi-illumination are performed. In Patent Literature 1, since the intensity of epi-illumination light is large and a direct reflected light component from a sample is large, the epi-illumination is substantially performed by leading the light into the first optical fiber bundle.